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How do you polish a firewall?

Ed_Wischmeyer

Well Known Member
Will be pulling an engine, and this seems like a good time to detail things firewall forward. So how do you polish a firewall? What kind of polish or abrasive, what kind of polisher / pad, what speed, etc?

thanks!

Ed
 
I bought a stainless polishing kit online from Caswell. Link to kit

I have pictures on my website if interested.

It is not a quick process. Stainless is very hard and it takes many passes with a lot of pressure to get it cleaned up. I used mostly the Green bar (least abrasive) and the liquid swirl remover since the stainless is typically in good shape. The lesson I learned is to use a lot of pressure. I never got a "mirror" finish but it was close enough.
 
I used the same product Randy did after he recommended it to me...works great, but it's no picnic. I didn't get a mirror finish either, but pleased with the results.

2-24-08-008w.jpg
 
I polished my RV8 firewall before I installed any items. I used Maquires (sp) metal polish that I got a local auto parts store. I used an old shop towel and about 1/2 hour to finish the job.

It came out pretty good, but not mirror perfect. I need to go back and touch it up now that I'm flying. I don't know how hard its going to be to polish around the firewall mounted stuff.
 
Some tips...

I've polished all sorts of parts for projects, aluminum, stainless, brass...

If you go to Grizzly.com and get the random orbital sander bonnets, they are okay. Start with prepolishing liquid, then red rouge, then green fine, then high polish for stainless pink. After all that, hit it with liquid car wax.

All of this should be done with separate bonnets for each grade compound. Sharpie mark them before starting. Apply even pressure, but let the machine do the work.

After an hour or so, you should be able to shave in the reflection!

One more thing, use proper respirator and eye protection and wear a painter's cover-up suit. After doing big polishing jobs, you get covered with all the strings from the polishing wheels/bonnets and all the black oxide that comes off.

You will look like a Yeti when done if you do it right.:D:eek:
 
Polish firewall

...okay, I only know how to Ukrainian a firewall. ( rimshot!)

..aren't you tempted to cover that beautiful piece of stainless with a nice, homely fireproof blanket?? If I had my engine off, that's what I'd be shopping for!

sorry....go ahead and buff away! mmmmmmmmm ... shiiiiiinnnnneeeeyyyyy!
 
Stainless Polishing

Ed,

Have never polished a firewall but I polish a lot of stainless pieces. I use buffing compounds from Busch cleaning products. You can find them through Ask.com or Google. These are normally used with a wheel on a buffer but you can use a buffing wheel on an electric drill as well. It is obviously easier prior to installation but it can be accomplished. Stainless will definitely polish to a mirror shine and retain that for years in the protected environment of an aircraft firewall.
 
A Van's firewall is made from semi-polished sheet material, so unless you're a fanatic I'd skip the compound and wheels....it doesn't need a lot of cutting. You can get 95% of a buffer finish with hand polishing. Since you never look directly into a firewall you can't tell the difference.

My favorite general purpose aluminum and stainless polish is Met-All:

http://www.wicksaircraft.com/catalog/product_cat.php/subid=8347
/index.html

They make a great brass polish too.
 
An alternative to polishing that renders a compelling result (at least in the examples I observed at a Boone Fly-in) is to burnish small circles onto to the stainless firewall, a technique sometimes referred to as "engine turning." The builders using the technique at Boone omitted just those areas of the firewall as to make RV-8 (or other lettering) jump out at you. Pretty dramatic effect. There once was a discussion about this but for the life of me I cannot find the information anywhere in the archives. Perhaps it was originally posted in the Test/Misc. area and has long since been deleted. Anyway, here is a picture of the intake ramps on my -6A using the "engine turning" technique. Hopefully, it will give you an idea of the finished look.

5x3m0w.jpg
 
Engine Turning

Here's another example of engine turning on my firewall. To do this, I laid out a 1" x 1" grid with a sharpie on the firewall and then used a 2" diameter Roloc scotchbrite wheel in a cordless drill. Took a while and I'm not sure it's worth the effort but it looks nice now.

Chris

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My favorite general purpose aluminum and stainless polish is Met-All:
Dan, I owe you a beer! I was walking through one of the exhibit halls at OSH and came across Met-All's booth. Remembering what you said I picked up a $5 tube of their AL & SS Polish. I'm just coming in from the shop and I must say how shocked I am with the results I was able to get from less than a minute of polishing... In that time I was able able to polish a 6" round area to a nice shine. It's not the perfect mirror finish you get with other products and tools, but it's certainly good enough for me. Amazing stuff!
 
Chris--

I tried some sample pieces of alum. before I left for OSH...Kept getting a bit of drill "runaway", and am not to anxious to try this on my firewall.

Any pointers?

BTW, It's already riveted to the rest of the fuse.

Thanks!
Joe
 
Joe,

I'm not sure how much help I can offer but I'll show you how I did it. FWIW, I'm not too sure I would do this on a firewall that's already mounted. I did it on my firewall before mounting anything and before bending it. But, for future fun, this is how I did it. First practice on a scrap of stainless shimstock or aluminum. If using aluminum, be aware that this will take most, if not all of the alclad layer off.

Scrap piece of stainless shim stock.

IMG_0436.JPG


I used some 2" Roloc finishing & polishing discs from McMaster (part#46325A55) and the disc holder also from McMaster (part# 46325A92)

IMG_0438.JPG


Since these are 2" discs, I laid out a grid approximately 1" x 1".

IMG_0437.JPG


I then just mounted the discs in a cordless drill and using the highest speed on the drill proceeded to polish each intersection of the grid. Use two hands on the drill and light pressure ( let the wheel do the work). Start the drill slowly to keep it centered and then quickly bring up the speed and the drill won't walk. Again, use light pressure. I polished each spot for 5 -10 sec. trying to be consistent on time.

IMG_0440.JPG


This small piece took about 15 mins start to finish including rounding up all the tools shimstock.

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Here's a shot showing how it matches what I did on the firewall and then an overall shot of the firewall.

IMG_0444.JPG


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Hope this helps,

Chris
 
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